If you have Windows Update set to run in the middle of the night (as most of us do), it is rather annoying to return to your computer in the morning only to find that it has automatically rebooted due to an installed update. There is a way to prevent this from occurring, but it does require a registry hack (Windows XP/Vista/7/8).
- Run regedit and browse to HKEY_LOCAL_MACHINESOFTWAREPoliciesMicrosoftWindows
- Create a new key under Windows and call it WindowsUpdate
- Create a new key under WindowsUpdate called AU
- With AU selected, in the right-hand pane right-click and create a new DWORD. Call itNoAutoRebootWithLoggedOnUsers
- Double-click the DWORD and give it a value of 1.
- Reboot and Windows Update will stop automatically rebooting your computer.